/*
 * Copyright (C) 2017-2019 Dremio Corporation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.dremio.dac.server;

import java.io.IOException;

import javax.annotation.Priority;
import javax.ws.rs.Priorities;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.container.PreMatching;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.UriInfo;

/**
 * Filter to get output media type from parameter and modify response accordingly
 * by overwriting {@link HttpHeaders#ACCEPT} header
 */
@PreMatching
@Priority(Priorities.HEADER_DECORATOR)
public class MediaTypeFilter implements ContainerRequestFilter {

  @Override
  public void filter(ContainerRequestContext requestContext)
      throws IOException {
    final UriInfo info = requestContext.getUriInfo();
    MultivaluedMap<String, String> parameters = info.getQueryParameters();

    String format = parameters.getFirst("format");
    if (format == null) {
      return;
    }
    requestContext.getHeaders().putSingle(HttpHeaders.ACCEPT, format);
  }

}
